Elmer #34 with Brake Cylinders

[propclock]

The title says most of it. Elmer's Engines has a Cross Twin Engine at chapter 34.
So I call it an Elmer #34. I was fortunate enough almost 20 years ago to see
an original design version running at my first visit to a BAEM show.
BAEM= Bay Area Emgine Modelers. I joined the club shortly there after.
I was given a pair of brake cylinders at one of our meetings years later.
What to do with a cylinder with a port at dead center? Well here it is .
The gift cylinders were too rough for use but the mental seed was planted
and I bought some new ones on ebay cheap. There they sat until recently.
With my wife home all the time and a serious dislike of gas fumes .
I.C. put on hold. for now. The engine is mostly according to plans But with 1"
pistons (4). The stroke is stock as is the basic layout. Obvious width changes .
The air supply valve was moved to the side because it made sense to me but it does
eliminate some cool motion stuff from the original design. I had to modify the air supply
because I made a light flywheel with the X pattern web, as in cross, flow design in mind.
The original air supply valve had long dead spots and a light flywheel really pointed this out. Hand testing lead to the solutions necessary with valve design and actuation.
I will give details to anyone interested but I did a youtube of it running in both finished and raw states,



Love this site, please ask any questions I have a lot of pictures if interest appears.

 

[el gringo]

The title says most of it. Elmer's Engines has a Cross Twin Engine at chapter 34.
So I call it an Elmer #34. I was fortunate enough almost 20 years ago to see
an original design version running at my first visit to a BAEM show.
BAEM= Bay Area Emgine Modelers. I joined the club shortly there after.
I was given a pair of brake cylinders at one of our meetings years later.
What to do with a cylinder with a port at dead center? Well here it is .
The gift cylinders were too rough for use but the mental seed was planted
and I bought some new ones on ebay cheap. There they sat until recently.
With my wife home all the time and a serious dislike of gas fumes .
I.C. put on hold. for now. The engine is mostly according to plans But with 1"
pistons (4). The stroke is stock as is the basic layout. Obvious width changes .
The air supply valve was moved to the side because it made sense to me but it does
eliminate some cool motion stuff from the original design. I had to modify the air supply
because I made a light flywheel with the X pattern web, as in cross, flow design in mind.
The original air supply valve had long dead spots and a light flywheel really pointed this out. Hand testing lead to the solutions necessary with valve design and actuation.
I will give details to anyone interested but I did a youtube of it running in both finished and raw states,



Love this site, please ask any questions I have a lot of pictures if interest appears.View attachment 117199

hi propclock,
I also belonged to BEAM in about the same timeframe. Never got to any meetings but attended several shows in Portland & Visalia. I showed some engines in a Visalia show, nicer bunch of guys are not to be found...Mike Rehmus always willing to help, I had some articles in his newly launched
magazine...met he and his wife at dinner in Portland as the were about to commit to the magazine.

Your Elmer's engine is beautiful. Are any plans around that are available?

Ray Monahan

 

[el gringo]

hi propclock,
I also belonged to BEAM in about the same timeframe. Never got to any meetings but attended several shows in Portland & Visalia. I showed some engines in a Visalia show, nicer bunch of guys are not to be found...Mike Rehmus always willing to help, I had some articles in his newly launched
magazine...met he and his wife at dinner in Portland as the were about to commit to the magazine.

Your Elmer's engine is beautiful. Are any plans around that are available?

Ray Monahan

 

[Tom 1948]

Beautiful engine and very good work. I just cant believe the price of brass nowadays.

 

[propclock]

hi propclock,
I also belonged to BEAM in about the same timeframe. Never got to any meetings but attended several shows in Portland & Visalia. I showed some engines in a Visalia show, nicer bunch of guys are not to be found...Mike Rehmus always willing to help, I had some articles in his newly launched
magazine...met he and his wife at dinner in Portland as the were about to commit to the magazine.

Your Elmer's engine is beautiful. Are any plans around that are available?

Ray Monahan

The plans came from JohnTom website
http://www.john-tom.com/ElmersEngines/34_crossTwin.pdfYes BAEM is a great club but was somewhat intimidating to me at first.
Your are building your first engine and a guy shows up with a blown V8.
Dwight Giles is now my best buddy. I have always gravitated to those I can learn from.
I am now the President of the club. My first show at the GoodGuys is a highlight in
my life.
I use primitive CamBam and can provide info if needed.

 

[Richard Hed]

The title says most of it. Elmer's Engines has a Cross Twin Engine at chapter 34.
So I call it an Elmer #34. I was fortunate enough almost 20 years ago to see
an original design version running at my first visit to a BAEM show.
BAEM= Bay Area Emgine Modelers. I joined the club shortly there after.
I was given a pair of brake cylinders at one of our meetings years later.
What to do with a cylinder with a port at dead center? Well here it is .
The gift cylinders were too rough for use but the mental seed was planted
and I bought some new ones on ebay cheap. There they sat until recently.
With my wife home all the time and a serious dislike of gas fumes .
I.C. put on hold. for now. The engine is mostly according to plans But with 1"
pistons (4). The stroke is stock as is the basic layout. Obvious width changes .
The air supply valve was moved to the side because it made sense to me but it does
eliminate some cool motion stuff from the original design. I had to modify the air supply
because I made a light flywheel with the X pattern web, as in cross, flow design in mind.
The original air supply valve had long dead spots and a light flywheel really pointed this out. Hand testing lead to the solutions necessary with valve design and actuation.
I will give details to anyone interested but I did a youtube of it running in both finished and raw states,



Love this site, please ask any questions I have a lot of pictures if interest appears.View attachment 117199

Thankyew for correcting my name for it. I put something on as it was from memory and it is indeed the Cross Twin not what I said. But I really appreciate seeing a working model. It appears to me that it wouldn't be too difficult to make. This is ABSOLUTELY WONDERFUL and I am very jealous. Can you tell me if you thimk it is difficult to make? How about your changed valve system? What about power and efficiency? Could you run steam with the delrin pistons? Just plain FABULOUS! I just finished drawing up the parts using AutoCAD so that I have a cleaner, printable form for the shop. It's not likely that I will get to start this soon as I just got a harvesting job and wish to finish other projects first. (Job so I can buy a better lathe.) And, Yes, I would like to see other photos.

Do you thimk the original valve system is flawed? I wonder if there is enough contact pressure to make that valve work correctly. A wobbler seems to work well enough with low pressure and the origninal valve system is basically like a wobbler, but what if the pressure is cranked up a bit? Would you be OK to show me the valve you designed? Is it rotary or what?

Yes, that motion would be absurd if it didn't work well.

 

[propclock]

O.K. thanks for the questions. We, BAEM, used to have shows and ran our stuff all day long on air, so I used Delrin. love the stuff. If you look close at Elmer's plans you will see the the supply ports on the rotary valve are at .25 radius. not the .217" radius that would cover the center portion of the slotted port. I ran it with a pair of vice grips for a flywheel
because I am an impatient guy. Ran great, but when I made a
"cool to me " flywheel , I found out the dead spots on each end
of the throws. So I made the supply ports .125 on .217 " ,
from pivot point. could be even larger than..125
Then instead of .25" valve throw from the crank
I increased it to ..348 . It really reduces " the dead zone"
The contact pressure is an issue I am sure if I ran it on steam
I would see all the leakage, for me delrin and air it is good enough.
My engine is 1" bore ~4x times the displacement of 1/2" bore.
The original plan had cool 90 degree reversal of the valve.
One more thing to confuse a non motor head.
Small detail
the brake cylinder had 2, 5mm bolts and a bleed screw on the face
I didn't like just using 2 bolts to hold it down to the base, so I used the
bleed screw assembly as a filler for a 6-32 screw tapped into its port.

 

[Richard Hed]

O.K. thanks for the questions. We, BAEM, used to have shows and ran our stuff all day long on air, so I used Delrin. love the stuff. If you look close at Elmer's plans you will see the the supply ports on the rotary valve are at .25 radius. not the .217" radius that would cover the center portion of the slotted port. I ran it with a pair of vice grips for a flywheel
because I am an impatient guy. Ran great, but when I made a
"cool to me " flywheel , I found out the dead spots on each end
of the throws. So I made the supply ports .125 on .217 " ,
from pivot point. could be even larger than..125
Then instead of .25" valve throw from the crank
I increased it to ..348 . It really reduces " the dead zone"
The contact pressure is an issue I am sure if I ran it on steam
I would see all the leakage, for me delrin and air it is good enough.
My engine is 1" bore ~4x times the displacement of 1/2" bore.
The original plan had cool 90 degree reversal of the valve.
One more thing to confuse a non motor head.
Small detail
the brake cylinder had 2, 5mm bolts and a bleed screw on the face
I didn't like just using 2 bolts to hold it down to the base, so I used the
bleed screw assembly as a filler for a 6-32 screw tapped into its port.

I would like to see that running with vice grips--just stand out of the line of fire. I just chekt my drawings and the ports are .091". I'm wondering if we are talking about the same thing? At the top of the (original design) there is a round valve that operates like a wobbler, turning aprox. 80-90deg letting the air into the center of the cylinders. Is this what you are talking about? Since you did it differnetly, maybe that is what you are talking about?

 

[propclock]

Yes 3/32 I believe, on a .25 " circle with a .25" crank throw.

 

[Richard Hed]

Yes 3/32 I believe, on a .25 " circle with a .25" crank throw.

Oh, OK, Now I understand. Well I can hardly wait (excitement, desire, jelousy fear want deprivation) to be able to start that little engine.

IN the mean time, I am also planning on building this milling attachment, I'm not sure if it is Elmer's or someone elses, maybe ME's but I have done it up in AutoCAD and show it here. Sorry for the ugly, gaudy colors, but that is so that I can see the parts when putting it together, else it would all blend in to each other and not really be understandable. It's not put together perfectly, just enough to understand the concept. Whoops, the *.bmp is "not allowed" . Maybe a JPEG?